A network service provider may store a service address for a customer in a database when the customer initially subscribes to the service. For example, a VoIP service provider may store addresses of VoIP customers in a database. In order to ensure that customers of VoIP service are able to access emergency services, the Federal Communications Commission (FCC) mandates VoIP services to be provided only at a location where E911 calls are supported (E911 services). For example, service providers may restrict access to the VoIP service only to the known service address of a customer. For example, if a customer has a VoIP service at home, a VoIP operator may suspend the customer's access to the VoIP service when he/she attempts to access the service from another location.